Currently, the turbocharging technology is becoming more and more popular for its capacity of effectively enhancing the efficiency of the engine. It has become one of the main trends for energy saving and environmental protection in the gasoline energy times. At present, a lot of electromagnetic valves are widely applied in the field of turbocharged engines. However, most electromagnetic valves existing in the market include an electromagnetic circuit comprising a coil winding wrapped around the coil holder, a static core, a dynamic core, a magnetic conductive disc and a magnetic cover, etc., wherein, the dynamic core is generally hollow and in most movably mounted on the guide pin with its radial outward surface. With the rapid development of electronic technology at home and abroad, the demand for all kinds of electromagnetic valves is growing, meanwhile, the requirement for leakage control of the electromagnetic valve is higher. However, the existing electromagnetic valves for turbocharger have the problems as follows:
1. The guide pin results in complex processing and installation in manufacturing, high production costs and unstable operations of the valve.
2. The electromagnetic relief valve for turbocharger is usually provided with a seal cover. The existing seal cover is plastically molded. It is relatively rigid and easy to become deformed after long period of application under high temperature, resulting in a greater leakage, which is difficult to control for rapid pressurization or depressurization.
3. Lathing method is usually applied in prior art to produce the V-shaped seal ring with high temperature resistance. The disadvantages of this approach are as follows: on one hand, it needs precision lathes and other expensive manufacturing equipment, and on the other hand, lathing method requires stricter purity of bar materials, resulting in the poor performance of the V-shaped ring with high temperature resistance. In prior art, the method of injection molding for production of the V-shaped ring with high temperature resistance also has corresponding problems. It proposes high requirements for the molds. And a long period of application under high or low temperature will result in serious deformation, therefore, it is difficult to control its sealing performance, and the leakage is not easy to reach the standard requirement.